直接看代码吧

#include <bits/stdc++.h>
using namespace std;
int s,v,t=10,h0=0,h=7,m=60;
int main(){
	cin>>s>>v;
	if(!s%v);
	else t++;
	t+=s/v;
	if(t>=60){
		h-=t/60;
		t=t%60;
	}
	m-=t;
	if(h<=0)h+=24;
	if(m==60){
		m=0;
		h+=1;
	}
	if(h/10==0&&h%10!=0)cout<<h0;
	cout<<h<<':';
	if(m/10==0&&m%10!=0)cout<<h0;
	cout<<m;
    return 0;
}

就#7#9一直不过